Why HDI PCB Board?

HDI stands for High Density Interconnect, and HDI PCBs (Printed Circuit Boards) are specialized circuit boards designed to have a high density of components and connections in a small area.

HDI PCBs are useful in applications where space is at a premium, such as in mobile devices like smartphones, tablets, and wearables. With HDI technology, circuit designers can achieve a greater number of connections between components on a smaller board, allowing for more complex and sophisticated electronics to fit into a smaller device.

HDI PCBs are also beneficial for high-speed and high-frequency applications, as they can reduce signal loss and interference. This is achieved through the use of microvias and buried vias, which allow for shorter signal paths and better signal integrity.

Overall, HDI PCBs are essential in many modern electronic devices, allowing for smaller and more powerful technology to be developed.

• Surface real estate

• Signal isolation

• Reduced signal antenna (less noise)

• Different component footprints top to bottom

• Robust PCB manufacturing and long-term board reliability on µBGAs (≤0.5mm)

  
  

Types of HDI

Types of Via

HDI Build Sequence

Case Study: Available Drill Spans Using Combined HDI Elements

Stacking HDI Structures

Reasons to stack HDI structures:

• Real estate – frees up surface routing

• Pinout of dense microBGA devices (≤0.5mm) for reliability and manufacturability

Constraints:

• Must be filled (resin or Cu filled/plated shut)

• Stacking microvias on buried vias can be a reliability concern on boards >.062” thick (> .093” is greatest risk) due to Z-axis thermal expansion

• No concern with stacking microvias on top of each other

• Staggered microvias should be .008” min from edge of microvia to the edge of the buried via